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- Jun 19, 2016
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Hello...for better or worse, I've been watching various youtube videos about diagnosing fried ECM's..etc. Some of the information....if true...is rather disturbing. Measuring voltages and resistances is not always enough, and that current draw is the most critical thing. A basic rule is that when resistance is low - current is high. Another basic rule is that if the current draw is greater than 1.2 Amps for a duration greater than 6 milliseconds, the ECM will likely get cooked.
On my Audi, one of the high pressure fuel pumps has low resistance. The specs are 448 to 800 ohms, and I measure about 35 ohms. Power to the various engine components on the Audi is supplied by a relay, not directly from the ECM, so by design the ECM appears to be protected from these kinds of issues.
But for vehicles where the ECM directly powers certain components, could a low resistance component...that may not always blow a fuse...damage the ECM?
On my Audi, one of the high pressure fuel pumps has low resistance. The specs are 448 to 800 ohms, and I measure about 35 ohms. Power to the various engine components on the Audi is supplied by a relay, not directly from the ECM, so by design the ECM appears to be protected from these kinds of issues.
But for vehicles where the ECM directly powers certain components, could a low resistance component...that may not always blow a fuse...damage the ECM?
